A double blind trial, was designed, in which 118 patients undergoing the removal of impacted wisdom teeth were randomly divided into the following groups; 41 patients received Metronidazole, 39 patients received Arnica Montana, 38 patients received the placebo. Metronidazole was more effective in pain control than Arnica (p less than 0.001) and placebo (p less than 0.01). It prevented swelling better than Arnica (p less than 0.01) and placebo (p less than 0.05) and was more effective in promoting healing than Arnica (p less than 0.01) and placebo (p greater than 0.02). Arnica Montana appeared to give rise to greater pain than placebo (p less than 0.05) and caused more swelling than the placebo (p less than 0.01).